1. Field of the Invention
The present invention is directed generally to a ventilation conduit damper assembly for use in a variety of angular mounted positions. More specifically, the present invention is directed to such a ventilation damper assembly provided with automatic temperature and pressure responsive actuating means whereby the amount of movement of the damper vane or vanes, over a preselected temperature and/or pressure range, is controlled and the vane or vanes will automatically close whether mounted in a vertical or horizontal plane or any plane therebetween.
2. Description of the Prior Art
Dampers for use in air conduits or ducts are generally well known and typically a damper assembly will consist of a movable vane or vanes which are positionable to control the amount of air flow through the conduit within which the damper is placed. Dampers are additionally often used in conjunction with ventilating systems in private homes and other buildings where it is desired to provide a measure of ventilation control.
In some areas of the country, where rather hot weather is experienced during at least a portion of the year, it is often desirable to provide a means for ventilating an otherwise confined portion of a building, for example, the attic in a private home, in order to minimize the buildup therein of excess heat and/or humidity. This ventilation is often provided by the use of a turbine air ventilator of a well known type in which wind causes the turbine blades to rotate, producing in effect a pumping action, assisting the air flow out of the area provided with the ventilating conduit.
While turbine ventilation systems are quite effective in promoting air flow, they have, in the past, suffered from the lack of an effective automatic means to control the amount of air removed. Obviously, the air flow should be at a maximum during hot weather when the temperature of the air to be ventilated is high, but just as obviously the ventilation should be much less when the temperature in the air to be ventilated is lower. Unnecessary ventilation during periods of cool temperatures may contribute to excess losses of heat and consequent increases in heating costs. While this problem of present ventilation systems is recognized, there had been no solution until the appearance of U.S. Pat. No. 4,123,001 issued to Stanley Kolt on Oct. 31, 1978. This device provides an automatic ventilator which permits ventilation during the heat buildup in a confined space, usually an attic. Prior to this invention by the same inventor as the present invention, the prior automatic adjustable dampers which had been contemplated or manufactured, as for example those disclosed in U.S. Pat. Nos. 1,737,054; 3,921,900; and 3,976,245 had been unable, under certain conditions of postionment, to perform their desired function in an effective manner, in that the angle in which they can operate is limited. Since it was recognized that there are numerous applications in which it would be desirable to mount a damper in other than a horizontal plane, the prior invention by the present inventor solved this problem. It now has become recognized that there are certain situations in which it is desirable to open the dampers in a conduit automatically regardless of overtaking even if the confined space has not reached or is not at the proper opening temperature.
Circumstances when such opening is desired can basically be attributed to situations when there is a pressure buildup in a confined space. For instance, it is quite commonplace to have a so-called whole house fan installed between the upper ceiling of the top story of a dwelling and the attic thereof. This fan sucks warm air out of the top story of the house and pumps it into the attic. Frequently, there is a back pressure built up in the attic attributable to the whole house fan which cannot be vented by a conventional temperature actuated damper because the attic does not reach the necessary temperature to trip the temperature responsive mechanism of the damper. When there is such a pressure buildup inside an attic, as a result of the use of the whole house fan either for cooling or more likely for general ventilation purposes such as when it is desirable to vent smoke or stale air from the house, the prior art will not permit exhausting of the attic air. In contrast, the present invention is configured such that this buildup in pressure will force the damper vanes of the present invention open so that ventilation can be accomplished.
The present invention has application for use in a flu such as in a heating system with solid, gaseous, or liquid fuels. For example, at the outlet or within a fireplace chimney or conventional home or industrial heating unit.
Another instance where opening of a damper in response to a differential in pressure is desirable is where a driven fan or turbine is disposed on the outer end of a ventilation conduit adjacent to the atmosphere. When this fan or turbine is activated for ventilation purposes, if the air within the attic is not hot enough to cause the temperature responsive mechanism to be triggered, no air can be withdrawn from the attic. In contrast, activation of such a fan or turbine, when used in conjunction with the present invention, will cause the vanes thereof to be sucked opened as a result of the pressure drop between the vanes and the fan this pressure drop having caused the ambient pressure in the attic once again to be greater than that in the conduit adjacent to the exhaust half thereof.
Additionally, if sufficient air flow is caused through a conduit by any means, a cooling effect can take place at a temperature actuated damper disposed therein and even though the confined space, such as an attic, is at a temperature sufficient to open the damper vane, the vane will remain closed. Such is not the case with the present invention since an air flow itself will cause opening of the damper thereof.
Therefore, the present invention overcomes the problems associated with the prior art by providing an automatic pressure and temperature responsive damper for use in a ventilation system wherein the damper can be opened in response to a preselected temperature or a preselected pressure.